I followed the instructions here:
More convenience managing large amounts of rigs
I tried with 7zip and now winrar but when I try to restore kemper says:
"This backup is damaged beyond repair. Please restore from another backup file."
I also noticed the original zip up file is about 2.3MB and after deleting all but 100+ rigs, it was down to 200kb - not sure if this is normal.
Anyone else having this issue? Am I doing something quirkly? It seems really straight forward so I'm not sure what I'm doing wrong.
Also, I did successfully restore the original backup so I know that the back up file is good.
Any help would be great.